Welcome Denny
I have two of those Sherwood S2200 tuners, they are great equipment for 1961 with over a dozen tubes, but mine do not have the multiplex adapter sub-chassis. It would be great to see a picture of them and the amp, which I am not familiar with.
as for the Magnavox, there may be a sticker with two-digit chassis number or stamped on the chassis. I know that series U41 or V39 was around that time.
Mags model numbers were not listed in Sams indexes. IIRC
the thread is probably rectangular tube TV, rather than early TV which is loaded with sets pre-1955.